# Quantum Cryptography II: How to re-use a one-time pad safely even if P=NP

@article{Bennett2014QuantumCI, title={Quantum Cryptography II: How to re-use a one-time pad safely even if P=NP}, author={Charles H. Bennett and Gilles Brassard and Seth Breidbart}, journal={Natural Computing}, year={2014}, volume={13}, pages={453 - 458} }

When elementary quantum systems, such as polarized photons, are used to transmit digital information, the uncertainty principle gives rise to novel cryptographic phenomena unachievable with traditional transmission media, e.g. a communications channel on which it is impossible in principle to eavesdrop without a high probability of being detected. With such a channel, a one-time pad can safely be reused many times as long as no eavesdrop is detected, and, planning ahead, part of the capacity of…

## 36 Citations

How to re-use a one-time pad safely and almost optimally even if P = NP

- Computer ScienceNatural Computing
- 2014

This work proposes an unconditionally secure scheme for encrypting classical messages under a shared key, where attempts to eavesdrop the ciphertext can be detected, and shows this is essentially optimal.

Two-way unclonable encryption with a vulnerable sender

- Computer ScienceInternational Journal of Quantum Information
- 2022

The proposed Unclonable Encryption protocol with the additional property that the sender's key material is allowed to leak even in the case of an unsuccessful run makes it possible to achieve secure quantum encryption even when one of the parties is unable to protect its keys against after-protocol theft.

Quantum Authentication and Encryption with Key Recycling - Or: How to Re-use a One-Time Pad Even if P=NP - Safely & Feasibly

- Computer Science, MathematicsEUROCRYPT
- 2017

We propose an information-theoretically secure encryption scheme for classical messages with quantum ciphertexts that offers detection of eavesdropping attacks, and re-usability of the key in case no…

Security proof for Quantum Key Recycling with noise

- Computer Science, MathematicsIACR Cryptol. ePrint Arch.
- 2018

A number of small protocol modifications are introduced and a security proof is provided based on a computation of the statistical distance between the real quantum state of the system and a state in which the keys are completely secure, which turns out to be a non-asymptotic result.

Uncloneable Quantum Encryption via Random Oracles

- Computer Science, MathematicsIACR Cryptol. ePrint Arch.
- 2019

This work formally defines uncloneable encryption, and shows how to achieve it using Wiesner's conjugate coding, combined with a quantum-secure pseudorandom function (qPRF), and shows security by adapting techniques from the quantum one-way-to-hiding lemma, as well as using bounds from quantum monogamy-of-entanglement games.

Optimal attacks on qubit-based Quantum Key Recycling

- Computer ScienceQuantum Inf. Process.
- 2018

From the optimal attacks determined, the required amount of privacy amplification is computed and hence the achievable communication rate (useful information per qubit) of qubit-based QKR, and 8-state encoding yields the highest communication rates.

Quantum data locking for high-rate private communication

- Computer Science
- 2014

We show that, if the accessible information is used as a security quantifier, quantum channels with a certain symmetry can convey private messages at a tremendously high rate, as high as less than…

PROOF FOR QUANTUM KEY RECYCLING WITH NOISE

- Computer Science
- 2019

The modified protocol has high rate not only for 8-state encoding, but also 6-state and BB84 encoding and a security proof based on a bound on the trace distance between the real quantum state of the system and a state in which the keys are completely secure.

Quantum Authentication and Encryption with Key Recycling

- Computer ScienceIACR Cryptol. ePrint Arch.
- 2017

We propose an information-theoretically secure encryption scheme for classical messages with quantum ciphertexts that offers detection of eavesdropping attacks, and re-usability of the key in case no…

Quantum cryptography beyond quantum key distribution

- Computer Science, MathematicsDes. Codes Cryptogr.
- 2016

This review article, aimed primarily at cryptographers unfamiliar with the quantum world, survey the area of theoretical quantum cryptography, with an emphasis on the constructions and limitations beyond the realm of QKD.

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